Water and sewage companies supply fresh water into homes. The water utility company supplies water for drinking and everyday use. The sewage utility company removes waste water and takes it to a treatment plant. The following are various terms associated with water and sewage utility companies.

Water Treatments – All water that comes out of the tap for drinking or taking showers and baths has been treated. Usually tap water has been treated with chemicals, like chlorine, to get rid of bacteria. However, there is concern for the safety of tap water, especially if it moves through old lead pipes.

Water Purification – Many products are sold to purify water, either in bottles or attachments to faucets. Technically, to purify water you must removed impurities, such as chemicals that have been added to the water, while still keeping the water clean. An example is distilled water.

Sewer Lines – the pipes that run from a sewer treatment plant to commercial and residential buildings. These lines remove waste water and treat it. Depending on the technology of the plant, some of the waste water is then recycled to be reused.

Septic Tanks – Sometimes called on-site sewer systems, septic tanks operate individually with each house and business. They work like main sewer lines except for the fact that instead of the water going to a treatment plant, it stays on the property and goes into a septic tank. From the septic tank the water goes into the drainfield, also on the property of the home, where the water is treated using microbes in the soil.

In the modern world, we take the supply of clean, potable water and the removal of waste for granted. Sewers have a long history. Although the health benefits of removing waste were probably little known, the benefits in terms of odor reduction were recognized by early civilizations and systems were built to either carry human waste away from homes or store it in cesspools. The oldest true flush toilet, with a cistern that fed water by gravity, has been found in the Minoan city of Knossos. Meanwhile, running water first showed up in the homes of wealthy Egyptians.
In our society, a utility company arranges for the removal of sewage. In some rural areas the modern equivalent of the cesspool, the septic tank, is commonly in use. Septic tank professionals need permission to install systems and should perform inspections and maintain regularly. Utilities purify water and supply it, although those same rural communities may not have access to it. In those cases, well or spring water is used, with systems to treat it as necessary. Well pumps are often electric.
The utility company often adds health promoting chemicals such as chlorine to the water. In the United States, tap water is expected to be drinkable. However, some people still purchase bottled water for drinking. Solar distilled water is popular in some areas. Water may come from aquifers, reservoirs or in rare cases desalinated seawater. This last technology remains rare and expensive. Much of a utility provider's job is to purify water to suitable levels.
Sewage is removed and flows to treatment plants. As water becomes seen more as a resource that needs to be conserved, recycle services could become common. Greywater systems reuse water from the kitchen sink for irrigating gardens. Rain may also be collected and used for irrigation.